fix typo

src/components/Legend.tsx

@@ -24,7 +24,7 @@ function Legend(props: LegendProps) {
       // check if response worked (no 404 errors etc...)
       throw new Error(response.statusText);
     }
-    const d = response.json(); // get JSON fr:om the response
+    const d = response.json(); // get JSON from the response
     return d; // returns a promise, which resolves to this data value
   };